Production of discharge effects



Patented Oct. 15, 1935 UNITEDJ STATES PATENT OFFICE rRon o'noN or DISCHARGE EFFECT ware No Drawing. Application April 13, 1932, Serial No. 605,115. In Great Britain May 19, 1931 4 Claims.

This invention relates to the coloration of textile materials, more particularly materials made of or containing cellulose acetate or other cellulose esters or ethers or animal fibres, for example 5 wool and silk.

It is well known that discharge effects may readily beproduced upon colored cotton materials by local application thereto of compositions containing sodium formaldehyde sulphoxylate. Fast colored discharges may be produced by this process by incorporatingein the discharge composition leuco compounds of vat dyestuffs in the form of alkali metal salts. In the case of cellulose acetate materials however discharge effects are'much less readily produced by means of discharging agents comprising sodium or other alkali metal formaldehyde sulphoxylate. With the aid of zinc formaldehyde sulphoxylate it is how- We have now observed that, as opposed to the water-soluble alkali metal compounds of leuco vat dyestuffs, the insoluble zinc compounds are compatible with zinc formaldehyde sulphoxylate, and at the same time are capable of coloring cellulose acetatematerials. They may therefore be employed in admixture with zinc formaldehyde sulphoxylate for the purpose of producing on cellulose acetate materials valuable discharge effects illuminated with vat dyestuffs. We have found in fact that the zinc compounds of leuco vat dyestuffs and also other insoluble metal compounds of vat dyestuifs are generally applicable in the coloration of cellulose acetate materials. Other cellulose esters and also cellulose others may be colored in the same manner and likewise animal fibres, for example'wool and silk.

Broadly, therefore, the present invention comprises the coloration of materials consisting of or containing cellulose acetate or other organic derivatives of cellulose or animal fibres by the application of vat dyestuffs in the form of insoluble metal derivatives of their leuco compounds. Insoluble metal compounds of leuco vat dyestuffs exhibit the important advantage that they are not strongly alkaline and may be applied under either neutral or even moderately acid conditions. They may therefore be utilized,

as explained above, for the coloration of discharges produced by means of zinc formaldehyde 5 sulphoxylate or by means of other heavy metal aldehyde or ketone sulphoxylates, and further they may be used to color materials, for instance cellulose esters and animal fibres, which are liable to damage by strongly alkaline baths or printing 10 compositions.

The zinc compounds of leuco vat dyestuffs have been found particularly convenient for application in accordance with the present invention, but other insoluble metal compounds may 15 be utilized if desired, for example compounds with cadmium, aluminium, tin, lead or iron. These insoluble metal compounds of leuco vat dyestuffs are conveniently prepared by interaction between the alkali metal salts of the leuco compounds and an appropriate metal salts, preferably such as are water-soluble. For instance, the dyestufl in question may be vatted with sodium hydrosulphite or other reducing agent and just sufficient caustic alkali to yield a solution of the leuco compound. 25 The solution thus obtained, if desired after filtration, may be treated with an aqueous solution of the appropriate metal salt, for example a concentrated solution of zinc chloride, whereby the desired metal compound of the leuco vat 30 dyestuif may be precipitated.

A wide range of vat dyestuffs havingaflinity for the materials to be colored may be applied by the new process. Particular mention may be made, especially for the coloration of cellulose ester and ether materials,'of the anthraquinone vat dyes containing one anthraquinone residue described in U. S. application S. No. 583,392 filed 26th December, 1931 and of indigoid dyestuffs, especially the indigoid dyestuffs described in U. S. application S. No. 583,406 filed 26th December, 1931, and derivatives of indigo and thioindigo.

he insoluble metal compounds of leuco vat dyestuffs, are conveniently applied to the materials in the form of aqueous suspensions or dispersions which may be prepared by any convenient means. For example, the metal compounds may be directly converted into aqueous suspensions or dispersions by mechanical treatment or by treatment with dispersing agents 0 and/or protective colloids or by the combination of these treatments. Thus a preparation adapted for application by printing may be made simply by stirring or grinding the metal compound with gumarabic or other thickening agent.

7 or .protective colloith, liguids or -adaptedfordyeingandprintingmlrposes.

iormedin the presence of mt. and/or protective colloids and suitable -1or dyeing and. printing directly obtained. Thus, a solution oian alkali salt oi a leuco compound may be precipitated with zinc chloride or other appropriate metal salt in .the presence oi a dispersing loid.

Preferably dispersion is eiiected in neutral or somewhat acid media, and dispersing agents or protective colloids, where employed, should be stable and capable oi exerting their or protective action in such media. As examples oi dispersing agentsor protective colloids of this character may be mentioned highly sulphonated compounds such as .highly sulphonated castoroil, sulpho aromatic fatty acids for example sulpho-naphthaline ricinoleic acid (see U. 8. Patents Nos. 1,840,572 and 1,694,413), basic agents soluble in acid media for example oleyl diethyl ethylene diamine or other basic derivativeoiaiattyacidalsostarcheaginnaglue, gelatin and the like.

If desired the dispersions or suspensions may bepreparedinconcentratediormadaptedto yield by dilution, with orwithou't addition of thickening agents or further agents preparations Wehavetoundthatitisnotessentialtoprepare theinsoluble metaloileucovat dyestuflspriortoapplicationtothematerlalas,it desired,theymaybe i'ormed onthematerial itself. For instance, the unreduced vat dyestuit inadmi xturewithareducingagentandametal oxide, carbonate, or other compoimdmaybe applied to the material and the latter then steamed, whereby the metal compound oi the leuco vat dyestufl isiormedinsitia ln'thisprocusthe.

presenceoistrmaikaliesshouldolooursebe avoided,asotherwhethereouiredmetalcompoundmay notbetormed. Thbmethodoicarryingcutthe newprocehismoreparticularlyappiicable whencolorations are to be callybyprintingorotberwlse.

The applicaflon of the or dispersions of the insolublemetai oileueo .vatdyatuii'stothematerialsmaybeeilected 'in-anydairedinannu,iorexampleby.dyeing,-

padding, or printingallovenoriocallybypu-inting, stencillingor other-method oilocal application. As explained previously however the vinventionhasbeeni'oundotgreatestvaluein etlectiimci'ilorat'irlisliyprintingorothei'modeoi localapplicaidmandmoreparticularlywhenthe vatdyestuitsaretobeusedi'ortheoolm'ationoi l dischargeaproduced by meansof sine formaldezbydesuiphosylatem'othermctalaldehydeor ketonesulphoaylatmwhicharedetrhnentaliyeiiectedbyeausiiealkali, Particularinentionmay bemadeoi'theapplicationotthemetalcompoimdsi'ortheilhimination'otsinci'ormaldehyde be'washed, soapedorsuhjectedto any other desirediinishingtreailnent.

celiuloseesterorethermaterialsooloredin lidesiredhoweveathemetalmay' agent and/or a protective colaocordame with the present invention may consist, for instance, of cellulose acetate as previously mentioned or of cellulose iormate, propionate or butyrate or the products obtainable by esteriiying cellulosic materials while retaining their fibrous 6 form, for example the product known as-immunised cotton" obtained by treating alkali cellulose with para-toluene-sulphonic chloride, or

they may consist of ethyl, methyl or benzyl cellulose or other ether of cellulose. The invention 10 is also applicable, as previously indicated. to the coloration of wool, silk and other animal iibres.

. Mixed materials comprising two or more types of the foregoing materials, tor example cellulose acetate and silk, or comprising one of the foregoing 1.; materials and another textilematerial, for example cotton or the regenerated cellulose type of artificial silk. may likewise be colored by the new When coloring materials consist'oi or contain cellulose esters or ethers the insoluble metal compounds or ieuco vat dyestuils may with advantage be applied in conjunction with alcohols, e. g. ethyl alcohol, phenols, e. g. hydroquinone, or other swelling agents for the material under treatment, Again when colored discharge eii'ects are to be produced the discharge composition may contain anthraquinone or other agents facilitating discharge with reducing agents.

The invention is illustratedbut not limited by so.

the tollifaing examples: sample 1 'Amaterialofcelluloaeacetateora mixtureoi' cellulose acetateandsilkisprintedll 'againwashedanddried.

The sine carbonate h conveniently prepared as a20% pastebyprecipitationoisincsulphatewith sodaashinaqueousaohition.

trample 2 Acelluloseacetateiabric dyedwithadischarges'sahle calming matter is ingprinting paste:

zincsaitoi'theleucocompoundotcibayelprinted with the followlowG 20 llethylated spirits. 10 Water 5 Gumarabicifl 40 Zinci'ormaldehydesuiphosylate. 28

. p r a e Afterprintingthematerialisageiiiorbminutes andthenehromemwashemsoapedand flnally rinsedand-dried. In thismanner iastyeliow dischargeeiiectsmaybeobtaineduponacolcred -lnplaceoi'thezinesaltoitheleucocanpotmd otclbayeliowqthecorrespondingsincoom poimdspreparedfromothervatdyestuiismaybe u. bLtAL HiNh' ct UYuwc; iLUlU TREATMENT at CHEWCAL MODIFI- 6 4CATION OF TEXTILES & FIBERS,

red Y, Algol violet BBN, Indigo LL, Indigo LII/2R and Caledofi jade green.

The zinc compound of the leuco vat dyestufl may be prepared in the following manner:

10 parts of dyestufi powder (e. g. Ciba yellow G) 8 parts caustic soda and 400 parts of water are well mixed and heated to 60 C. About 16 parts sodium hydrosulphite are added with good stirring until a clear vat is obtained. This solution is filtered to remove any insoluble matter and whilst still warm a solution of 10 parts of zinc chloride in 30-40 parts of water is added. The zinc salt of the leuco compound separates as a flocculent cream-colored precipitate and is filtered oil, washed with a very small quantity of water and retained as an aqueous paste.

What we claim and desire to secure by Letters Patent is: a

1. Process for the production of discharge effects on materials comprising organic derivatives of cellulose which comprises applying locally thereto a discharge composition containing zinc employed, for example, Ciba scarlet G, Durindone formaldehyde sulphoxylate and a water-insoluble metal compound of a leuco vat dyestufl.

2. Process for the production of discharge effects on materials comprising cellulose acetate which comprises applying locally thereto a discharge composition containing zinc formaldehyde sulphoxylate and a zinc compound of a leuco vat dyestufi.

3. Process for the production of discharge effects on materials comprising cellulose acetate which comprises applying locally thereto a discharge composition containing zinc formaldehyde sulphoxylate and a zinc compound of a leuco vat dyestufi of the indigoid series.

4. Process for the production of discharge effects on materials comprising cellulose acetate which comprises applying locally thereto a discharge composition containing zinc formaldehyde sulphoxylate and a zinc compound of a leuco compound of an anthraquinone dyestufi containing a 20 single anthraquinone nucleus.

GEORGE HOLLAND ELLIS. JOHN ALLAN. 

